Tachycardia

Tachycardias ("fast heartbeat") are usually categorized as either ventricular tachycardia, involving only the ventricles, or supraventricular tachycardia, involving both the atria and the ventricles. The definition of "too fast" usually depends upon the person's age and physical activity.

What causes Tachycardia?

Most often tachycardia is caused by an abnormal origin and conduction of the electrical impulse. Tachycardia is always classified by location -- ventricular tachycardias start in the heart's ventricles (lower chambers), while supraventricular tachycardias arise higher in the heart — either in the upper chambers (atria) or the middle region.

What are the symptoms of Tachycardia?

Symptoms can include the sensation of rapid heart action, (palpitations), dizziness, lightheadedness, fainting or near fainting. Heartbeats may have either a regular or irregular rhythm. Rapid heart beating in the ventricles — called ventricular tachycardia — can be life-threatening. The most serious cardiac rhythm disturbance is ventricular fibrillation, where the lower chambers quiver and the heart can't pump any blood.

How is Tachycardia treated?

Trained medical professionals can normalize both ventricular tachycardia and ventricular fibrillation with electrical shock (cardioversion) if the patient receives help quickly. Chronic or recurrent rapid heartbeat can sometimes be controlled with medications and by identifying or destroying the focus of rhythm disturbances. An effective way of correcting these life-threatening rhythms is implantation of an electronic device called an implantable cardioverter defibrillator or ICD.